Laptops forum


how do I isolate issue ofdead screen? external monitor works

by biostevef / January 1, 2013 2:47 AM PST

The screen on my satellite L675D quit working. It had not gone anywhere recently, just sitting on my desk so not dropped or anything like that. I hooked up an external monitor and it displays correctly. Anyone know how to test if it is the screen, or transformer? I would hate to order a new screen and have it still not work

Answer This Ask For Clarification
Discussion is locked
You are posting a reply to: how do I isolate issue ofdead screen? external monitor works
The posting of advertisements, profanity, or personal attacks is prohibited. Please refer to our CNET Forums policies for details. All submitted content is subject to our Terms of Use.
Track this discussion and email me when there are updates

If you're asking for technical help, please be sure to include all your system info, including operating system, model number, and any other specifics related to the problem. Also please exercise your best judgment when posting in the forums--revealing personal information such as your e-mail address, telephone number, and address is not recommended.

You are reporting the following post: how do I isolate issue ofdead screen? external monitor works
This post has been flagged and will be reviewed by our staff. Thank you for helping us maintain CNET's great community.
Sorry, there was a problem flagging this post. Please try again now or at a later time.
If you believe this post is offensive or violates the CNET Forums' Usage policies, you can report it below (this will not automatically remove the post). Once reported, our moderators will be notified and the post will be reviewed.

All Answers

Collapse -
In this case you have it fixed for you.
by R. Proffitt Forum moderator / January 1, 2013 2:54 AM PST

That's what service shops do for you. They take on the risk that if they order the wrong part, they set it right.

In our shop the test to see if it's the screen is to fit a new screen. Some of your newer technicians do ask if there's another way.

Collapse -
by R. Proffitt Forum moderator / January 1, 2013 2:56 AM PST

At the top of this forum are tips and bonus material from a laptop repair book. I can't tell if you have a dead screen or a dead back light. But the top posts and the material there do tell you how to sniff that out for free.

Collapse -
great diagrams!
by biostevef / January 1, 2013 3:19 AM PST

Thanks R. Proffitt, I had gone through the decision tree and was about to take it apart but in thinking through that realized if there wasn't a loose connector I would need to order a new screen but am concerned that it may be the transformer. I hate digging into something, ordering parts and ending up taking it to a shop anyway...

I am guessing that there is no way to test the hardware involved and it is a parts swap deal?

Collapse -
Let me tell a little story.
by R. Proffitt Forum moderator / January 1, 2013 4:16 AM PST
In reply to: great diagrams!

Long ago I wrote tester code for machines that would test parts. Back then you would take the part to the testing area and we had jigs and testers for each part of the system. On average each tester and it's jig ran about a million bucks each. Over the years this came down a little so we averaged out to 100K not including the cost of the test software.

As I moved to other companies you can imagine they didn't want to invest that much so we moved to what we called hot swap testing. That is, you could swap a board or item into a known working system to see if the part was still good. That sort of testing is pretty cheap.

I hope this story helps you understand that testing a part the right way could cost about a thousand times the cost of the part or entire system.

Collapse -
swapped in new monitor, now stuck in test pattern
by biostevef / January 5, 2013 1:10 AM PST

I ended up ordering and installing a new monitor. Initially it didn't come on but after changing the resolution on an external monitor, new unit started flickering and is now cycling through different colors and test patterns. It works but seems stuck. I purchased the new screen from "screensurgeons", paying quite a bit more assuming there was some tech support, WRONG! Even a question of if I should be smelling a burning wiring smell were answered by the same canned response of "it could be multiple issues, take to repair facility". The device manager doesn't indicate any problems, changing resolution hasn't helped. How do I get this seemingly functioning new monitor to get out of the test mode and render my desktop?

Collapse -
There are only a few parts to a laptop display.
by R. Proffitt Forum moderator / January 5, 2013 2:06 AM PST

I usually see the LCD (natch) the backlight system and motherboard. Then the cables to connect such. If the monitor does not work as expected and it's some external monitor then the motherboard becomes suspect.

If this is one of the known failing models such as that dv6000 line we swap the motherboard.

Did you smell burned wiring? Is that why you put that in your post?


Collapse -
no smoke
by biostevef / January 5, 2013 11:25 AM PST

Bob, I did smell burning wiring, kinda strong but it has gone away. Mine is a Toshiba Satellite L675D. The external monitor works fine and the new screen in the laptop is cycling through red, green, blue, gray, dark gray, checks and white, over and over again so I think the new monitor works but is not initializing or something. Since it is "working" but not displaying the startup screen, I am puzzled. F5 doesn't make it come on either...

Collapse -
I'm not puzzled.
by R. Proffitt Forum moderator / January 6, 2013 1:02 AM PST
In reply to: no smoke

We see such too often. We know to swap cables first and inspect all boards for any scorch marks. It's rarely done as the cost to repair such a laptop can exceed a replacement but your story does not bode well.

Popular Forums
Computer Help 49,613 discussions
Computer Newbies 10,349 discussions
Laptops 19,436 discussions
Security 30,426 discussions
TVs & Home Theaters 20,308 discussions
Windows 10 360 discussions
Phones 15,802 discussions
Windows 7 7,351 discussions
Networking & Wireless 14,641 discussions

CNET Holiday Gift Guide

Looking for great gifts under $100?

Trendy tech gifts don't require a hefty price tag. Choose from these CNET-recommended useful and high-quality gadgets.